Violence in a few major cities drove the national murder rate higher in 2016, according to new FBI statistics.

MATT FORD 5:57 PM ET

… Chicago ended 2016 with 762 murders, a whopping 58 percent jump over 2015’s total. Baltimore experienced its second-deadliest year on record with 358 murders, surpassing the previous record set in 2015.

That disparity could be felt in the national stats. John Pfaff, a Fordham University law professor who studies crime statistics, noted on Twitter that 22 percent of the nationwide increase in murders came from Chicago alone. But inside Chicago itself, 50 percent of the homicide rise came from just five neighborhoods, which account for only 9 percent of the city’s overall population. Those neighborhoods, in effect, account for 10 percent of the national increase in murders. …

What’s driving the increases in violence in the affected cities isn’t clear. Researchers in Chicago have struggled to find any direct causal factors behind the jump in gun violence there. Shootings and murders noticeably rose around the time that the Chicago Police Department released a video of officers killing 17-year-old Laquan McDonald in November 2015, but it’s uncertain if a subsequent drop in police street searches played a role.

In other words, the giant spike in homicides in Chicago’s black neighborhoods started on the day in November 2015 when BLM/ACLU scored a huge political victory over CPD. But causality is all very mysterious. As David Hume said, how can we be sure the rock falls to the ground because you released it? Maybe it was just a big coincidence? Who really knows?